The present invention relates to stacks of thin films used as capacitors.
It is well known in electronic circuits to use capacitors. Printed circuit boards (PCBs) have a limitation of using roll form or powder/electrolytic capacitors suspended over or under the board. It would be desirable to have a flat capacitor that can be attached directly to the board, or be integrated in the board with adequate electrical parameters and stability. As such, it is an object of the invention to provide such a capacitor.
It has been discovered that this object can be met by a capacitor that includes alternating layers of tantalum pentoxide or niobium pentoxide and an electrically conductive polymer film such as H.C. Starck, Inc.""s Baytron(copyright) line of polythiophene-based polymers. Advantageously, many types of thin conductive polymer films can be used.
The invention relates to a thin film capacitor that includes (a) a substrate, (b) a first polymeric film comprising an electrically conductive polymer located on the substrate, (c) a pentoxide layer selected from the group consisting of tantalum pentoxide, or niobium pentoxide, and mixtures thereof, located on a surface of the first polymeric film, (d) a second polymeric film comprising a conductive polymer located on a surface of the pentoxide layer.